<template>
  <view>
    <view class="scroll-view-container">
      <!-- 左侧的滑动区域-->
      <scroll-view scroll-y="true"  :style="{height:wh+'px'}" class="left-scroll-view">
        <block  v-for="(item,i) in cateList" :key="i">
          <view :class="['left-scroll-view-item', i===active ? 'active':'']" @click="activeChanged(i)">{{item.cat_name}}</view>
        </block>
        
      </scroll-view>
      <!-- 右侧的滑动区域-->
      <scroll-view scroll-y="true"  :style="{height:wh+'px'}" class="right-scroll-view" :scroll-top="scrollTop">
         <view class="cate-lv2" v-for="(item2,i2) in cateLevel2" :key="i2">
            <view class="cate-lv2-title">{{item2.cat_name}}</view>
            <!-- 动态渲染三级分类的列表数据-->
              <view class="cate-lv3-list">
                <!-- 三级分类Item项-->
                <view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3" @click="gotoGoodsList(item3)">
                  <!-- 图片-->
                  <image :src="item3.cat_icon.replace('dev','web')"></image>
                  <!-- 文本-->
                  <text>{{item3.cat_name}}</text>
                </view>
              </view>
         </view>
      </scroll-view>
    </view>
    
    
    
    
  </view>
</template>

<script>
  export default {
    data() {
      return {
        //当前设备可用的高度
        wh:0,
        cateList:[],
        active:0,
        cateLevel2:[],
        scrollTop:0
      };
    },
    onLoad() {
      const sysInfo  =uni.getSystemInfoSync()
      this.wh=sysInfo.windowHeight
      this.getCateList()
      this.getCateLevel2()
    },
    methods:{
      async getCateList(){
        //发起请求
        const {data:res} = await uni.$http.get('/api/public/v1/categories')
        //判断是否获取失败
        if(res.meta.status!==200) return uni.$showMsg()
        //转存数据
        this.cateList=res.message
      },
      async getCateLevel2(){
        //发起请求
        const {data:res} = await uni.$http.get('/api/public/v1/categories')
        //判断是否获取失败
        if(res.meta.status!==200) return uni.$showMsg()
        //转存数据
        this.cateLevel2=res.message[0].children
        console.log(this.cateLevel2);
      },
      activeChanged(i){
        this.active=i
        this.scrollTop=this.scrollTop===0?0.1:0
        //重新为二级分类赋值
        this.cateLevel2=this.cateList[i].children
      },
      //跳转到商品列表页面
      gotoGoodsList(item){
        uni.navigateTo({
          url:'/subpkg/goods_list/goods_list?cid='+item.cat_id
        })
      }
    }
  }
</script>

<style lang="scss">
.scroll-view-container{
  display: flex;
}
.left-scroll-view{
  width: 240rpx;
}
.left-scroll-view-item{
  background-color: #f7f7f7;
  line-height: 120rpx;
  text-align: center;
  font-size: 24rpx;
  
  &.active{
    background-color: #FFFFFF;
    position: relative;
    
    &::before{
      content:'';
      display: block;
      width: 6rpx;
      height: 60rpx;
      background-color: #C00000;
      position: absolute;
      top:50%;
      left: 0;
      transform: translateY(-50%);
    }
  }
}

.cate-lv2-title{
  font-size: 24px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}
.cate-lv3-list{
  display: flex;
  flex-wrap: wrap;
  .cate-lv3-item{
    width: 33.33%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    margin-bottom: 10px;
    
    image{
      width: 60px;
      height: 60px;
    }
    
    text{
      font-size: 12px;
      
    }
  }
}
</style>
